dirstate walking optimizations The repo walking code introduces a number of calls to dirstate.map.copy(), significantly slowing down the walk on large trees. When a list of files is passed to the walking code, we should only look at map entries relevant to the file list passed in. dirstate.filterfiles() is added to return a subset of the dirstate map. The subset includes in files passed in, and if one of the files requested is actually a directory, it includes any files inside that directory tree. This brings the time for hg diff Makefile down from 1.7s to .3s on a linux kernel repo. Also, the diff command was unconditionally calling makewalk, leading to an extra pass through repo.changes. This patch avoids the call to makewalk when commands.diff isn't given a list of patterns, cutting the time for hg diff (with no args) in half. Index: mine/mercurial/hg.py ===================================================================

#!/bin/sh

mkdir t
cd t
hg init
echo This is file a1 > a
echo This is file b1 > b
hg add a b
hg commit -m "commit #0" -d "0 0"
echo This is file b22 > b
hg commit -m"comment #1" -d "0 0"
hg update 0
rm b
hg commit -A -m"comment #2" -d "0 0"
# in theory, we shouldn't need the "yes k" below, but it prevents
# this test from hanging when "hg update" erroneously prompts the
# user for "keep or delete"
yes k | hg update 1
# we exit with 0 to avoid the unavoidable SIGPIPE from above causing
# us to fail this test
exit 0